Location: Kodihalli, Indira Nagar, Bangalore   (Borewell was done in July 2008)
Bore diameter: 6.5" with 2mm MS casing up to 80 ft and 10" PVC casing up to 55 ft
Water source: Got first (1/2") at 270 ft; second (3") at 510 ft; bore depth: 534 ft
Targeted source: 3" at 510 ft;
Pump: 5HP submersible Pump @ 508 ft depth

Earlier:
a) In the beginning yield was very good, having clear water - used to fill overhead tank serving 8 apartment in 1 hour
b) Since last 3 month yield dropped suddenly and now we get very little (but continuous) water - 5 bucket of water in 1 hour
c) Water is still clear, no trace of mud or gray water

Steps taken:

1. Called the driller, on inspection he indicated slit / sand formation above motor.
2. However he is not very sure why this happened or what going on inside.
3. He tried taking out Motor using compressor mounted on truck but effort failed as Motor is trapped in silt/sand

Questions:

4. What option we have to save the bore as well as Motor?
5. Is there any way to remove the stuck motor from the well?
6. Can we re-drill the borewell inside the open well??? What will happen to motor left inside?
7. Most efficient way to clean the borewell - high pressure jetting and cleaning or pipe dope/oil mud solvent etc...etc – any deep bore cleaning agency in Bangalore / around ?
8. Driller was suggesting to cut leave the motor and insert new motor. Is there any chance of getting good water yield??? At what height new Motor should be kept to get good water??? Any risk???
9. Contact details of suggested people / agency in Bangalore?

Kumar
mankumar@yahoo.com